Synapturanus latebrosus sp. nov. Synapturanus sp. “ Caquetá ” Holotype (Fig. 3). SINCHI-A 839 (MOM 2517), adult female, collected at finca El Cairo, vereda Sinaí, Municipio Morelia, Departamento Caquetá, Colombia, (01°23′31.7″ N, 75°45′06.2″ W), ca. 278 m., on August 4, 2011 by Yunner Fabian González, Diego Huseth Ruiz, Doris Laurinette Gutiérrez, and Mariela Osorno-Muñoz. Paratopotypes. SINCHI-A 840-841 (MOM 2518-2519), adult females, and SINCHI-A 842 (MOM 2520), cleared and double-stained specimen, SINCHI-A 843-845 (MOM 2521-2523) adult males, all collected with the holotype. Paratypes. Female SINCHI-A 2678 (JARM 139) (Fig. 3B) and male SINCHI-A 2679 (JARM 140) a cleared and double-stained specimen, collected at hacienda Villa Mery, vereda Sinaí, Municipio Morelia, Departamento Caquetá, Colombia (01°24′00.1″ N, 75°43′52.3″ W), 218 m., on December 16, 2015; female SINCHI-A 2703 (JARM 172), collected at vereda La Mono, Municipio Belén de los Andaquíes, Departamento Caquetá, Colombia, (01°18′27.8″ N, 75°48′13.9″ W), ca. 262 m., on February 18, 2016; females: SINCHI-A 5642–5643 (JARM 220- 221) collected at vereda Alto Caldas, Municipio Florencia, Departamento Caquetá, Colombia (01°39′N, 75°37′W), ca. 560 m., on 01 April, 2016; female SINCHI-A 5671 (JARM 254) collected at finca Alsacia, vereda la Primavera, Municipio Florencia, Departamento Caquetá, Colombia (01°39′ 4.87″ N 75°37′4.7″ W), ca. 530 m., on April 23, 2016, by Julián Andrés Rojas Morales, and Fabián Andrés Cabrera Vargas. Females: SINCHI-A 258–259 (MOM 1840 -1841) (Fig.3A), collected at vereda La Recreo, Municipio Solita, Departamento Caquetá, Colombia (0°55′39.2″ N, 75°40′35″ W), ca. 220 m., collected by Hernándo Trujillo on October 09, 2009. Referred specimens. Males SINCHI-A 846–847 (MOM 2524-2525), female SINCHI-A 848 (MOM 2526), all juveniles collected along with the type series, male SINCHI-A 5665 (JARM 248) collected at finca Alsacia, vereda la Primavera, Municipio Florencia, Departamento Caquetá, Colombia (01°39′ 4.87″ N 75°37′4.7″ W), ca. 530 m. on April 23, 2016, by Julián Andrés Rojas Morales, and Fabián Andrés Cabrera Vargas. Diagnosis. A species of Synapturanus diagnosed by the following combination of characters: 1) SVL median size: adult females 20.0–22.0 mm (χ = 20.9 ± 0.3, n = 8), adult males 18.1–19.0 (χ = 18.7 ± 0.3, n = 3 mm), 2) stout and elongated body, 3) head narrower than body, snout pointed in dorsal view, rounded in lateral view, and ventrally distinctly projecting beyond the anterior edge of the upper jaw, 4) symphysis of lower jaw with an unpigmented notch and external nares bear a wide and unpigmented rim, 5) tympanum indistinct, tympanic annulus visible below the skin, particularly its anteroventral edge, 6) vocal slits absent, 7) choanae rounded, larger in diameter than the unpigmented rim of the external nares, 8) vomerine teeth absent, 9) hand formula III>IV>II>I, digits becoming thinner towards their distal ends, rounded or slightly pointed finger tips, fingers bordered by a thin fringe, interdigital membrane absent, 10) subarticular tubercles absent; thenar tubercle elongated, palmar tubercle rounded with undefined edges, 11) adult males bear an elongated gland on the internal surface of the anterior forearm extending half of its length and broader at the wrist, 12) toe lengths IV>III>V>II>I, toes are thin and subcylindrical with a slight distal rounded or lanceolate widening, except toe I which is pointed, toes narrowly fringed, fringes more distinct distally and around the distal expansion, toes without webs, 13) inner metatarsal tubercle small and elongated, outer metatarsal tubercle absent, subarticular tubercles absent, subarticular spots unpigmented on toes, 14) skin folds on knee, heel, and wrist, 15) cephalic groove distinct, extending over the tympanum reaching and slightly extending beyond the lower jaw, 16) in life, upper surfaces of body uniformly brown, lighter brown on the area of the cephalic groove, tympanum brownish, and body flanks orange with a greyish brown ventral area, 17) light canthal stripe present or absent; if present, dorsal to the nares and the eyes, canthal stripe continuous or broken into a series of variable size spots; confluent or not on the distal tip of snout; posteriorly, the canthal stripe could reach the area over the tympanum or above the shoulder, 18) ventral surfaces overall brown, darker on edges of mandible, snout, arms, and hidden surfaces of legs and feet; lighter on thighs, chest, and edges of abdominal region; medially the belly has a narrow and irregular shaped whitish and translucent area, hands and feet dark brown; thenar, internal metatarsal tubercles, subarticular surfaces and distal digits without coloration, 19) elongated forearm gland cream-colored in preserved specimens extending from the wrist to half the length of the forearm. Synapturanus latebrosus sp. nov. differs from S. rabus (traits in parenthesis) by its larger size, adult females SVL 20.0-22.0 mm (vs. 17.2-19.0 mm), adult males SVL 18.1-19.0 mm (vs. 16.2-16.6 mm), a shorter tibia length TBL/SVL 38% in females and 37% in males (vs. 41% in both sexes). Eyes are smaller in S. latebrosus sp. nov. ED/ SVL is 54% (vs. 73%) and the ratio of the eye diameter to the eye-nare distance is also smaller, ED/END females χ = 0.5 (vs. 0.8), ED/END males χ = 0.6 (vs. 0.9) (Tables 2 and 3). In life, S. latebrosus sp. nov. has greyish ventral flanks (vs. overall dark brown); canthal stripe, if present, extending to the shoulder area (vs. canthal stripe may extend onto the body); posterior limbs without spotting (vs. most specimens have irregular light spots on one or both legs), tympanum partially hidden (visible tympanum). Synapturanus latebrosus sp. nov. males are smaller (SVL 18.1-19.0 mm) than S. mirandariberoi (SVL males 27.0- 31.7 mm), S. salseri, (SVL males 23.7-26.4 mm), S. zombie (SVL males 37.0- 40.6 mm), S. mesomorphus (SVL males 22.9-26.0 mm), and S. ajuricaba (SVL males 29.3-33.2 mm); S. latebrosus is larger than S. danta (SVL males 17.6-17.9). Adults of Synapturanus danta and S. latebrosus sp. nov. have a uniform dark brown dorsal coloration in life whereas the dorsum of S. mirandariberoi, S. salseri, S. zombie, S. mesomorphus, and S. ajuricaba have noticeable mottled patterns made up of speckles, spots, or blotches. The forearm gland is not conspicuous in life in Synapturanus latebrosus sp. nov. and S. rabus (i.e., gray-brown, similar to the rest of the arm), whereas in S. salseri and S. mirandariberoi it was described as a pale wrist gland contrasting with the darker coloration of the rest of the arm (Pyburn, 1976). Furthermore, the gland of S. salseri is protuberant on the dorsal and inner area of the distal forearm and becoming slightly triangular with its apex towards the posterior forearm; in S. latebrosus the gland is slightly wider on the wrists and narrowing posteriorly, in some specimens reaching the midpoint of forearm. Description of the Holotype. An adult female with two large, unpigmented ovarian eggs (3.6 and 4.0 mm diameter), body smooth, slightly ovoid in dorsal view, SVL = 21.5 mm; head triangular in shape, broader than longer (HW = 5.9 mm, HL = 5.5 mm); snout tip acuminate, snout projects beyond the anterior edge of the upper jaw (SL/SW = 0.6), nostrils with a distinct light rim, directed laterally, the distance from the eye to the nostril is 2.0 mm, being twice the diameter of the eye; canthus rostralis defined, slightly concave, loreal region marked by a distinct groove that extends from the anteroventral edge of eye to the posteroventral edge of nostril, eyes small and slightly protruding, interorbital area concave, IOD = 2.5 mm; occipital groove indistinct across the head and tympanum and visible just beyond the jaw; tympanum mostly concealed, anteroventral edge of tympanic ring barely visible, upper jaw distinctly projecting beyond lower one, with an unpigmented median notch in the anterior end of the lower jaw; the tongue is as wide as the oral cavity, its posterior edges are thin and wide; vomerine teeth absent; choanae round and widely separated. Anterior and posterior limbs short and robust, hands without interdigital membranes, finger relative lengths III>IV>II>I, fingers narrowing distally with distal tips pointed or rounded, slightly fringed, subarticular tubercles absent, subarticular area light colored, thenar tubercle elongated to oval, light colored and located at the base of finger I; distinct fold on knee and heel, less distinct folds also on wrist and metatarsal area; toes overall subcylindrical and slightly broader and rounded distally, fringes noticeable in toes I, II and distally in toes III, IV, V, interdigital membrane absent, in lateral view the distal tip of the digits are slightly flattened, subarticular areas light colored without subarticular tubercles, inner metatarsal tubercle very small, elongated, placed at base of toe I, outer metatarsal tubercle absent, toe formula IV>III>V>II>I; tibia length 8.3 mm, about 39% of snout–vent length. Live coloration. Dorsal surfaces uniformly brown, except the cephalic groove that is lighter; ventral body flank greyish brown; lateral head anterior to the arm light brown, rim of nares and tip of snout grey; tympanum brown/ slightly orange; iris dark brown, canthal stripe formed by very small and discontinuous cream spots that do not reach the shoulder, ventral surface brown, belly with a narrow, medial, and unpigmented area; dorsal surfaces of hands and feet brown, articulation and distal tips of digits unpigmented, ventrally dark brown with unpigmented subarticular areas; a black spot on the external region of the right wrist. Coloration of Preserved Specimens. Dorsal surfaces brown, light brown around the occipital groove on top head, anterior body flank brown, medial and posterior body flank brown-cream, ventral surfaces of throat, chest, arms and legs light brown cream, central belly light cream, ventral surfaces of hands and feet dark brown, unpigmented subarticular surfaces, and tips of digits cream-colored (Fig. 4). Measurements of Holotype (mm). SLV 21.5, HL 5.5, HW 5.9, HL/ESD 1.6, SL/SW 0.6, ESD 3.5, END 2.0, ED 1.0, ED/END 0.5, IOD 2.5, TBL 8.3, TBL/SVL 0.4 Variation in the type series. Measurement data of the type series are given in Table 2 and Table S2. Overall, the type series agrees with the holotype coloration. Two adult females (SINCHI-A 840 and SINCHI-A 5643) lack canthal stripes, three adult males (SINCHI-A 843-845) and five females (SINCHI-A 841, SINCHI-A 2678, SINCHI-A 2703, SINCHI-A 5642 and SINCHI-A 5671) have a canthal stripe being less distinct in the holotype. The medial unpigmented area of belly is variable, in two females (SINCHI-A 840 and SINCHI-A 841) it extends toward the ventral flanks, in males the unpigmented medial area bears a few small brownish dots. Etymology. Latin adjective, meaning ignored, alluding to the ecological and behavioral habits that make the species imperceptible and probably even allow it to live in forest fragments, as small as those found in the type locality. Distribution (Fig. 4). The northernmost locality currently known for Synapturanus latebrosus sp. nov. is the Municipio Florencia, Departamento Caquetá; likely the species has a continuous distribution from the Municipio Morelia and Belén de los Andaquíes to Municipio Solita, north of the Caquetá River. Tadpole and Advertisement Call. Unknown Natural History. The holotype and paratopotypes of Synapturanus latebrosus sp. nov. were collected in a fragment of primary forest (Synapturanus latebrosus sp. nov. Overall, the skull of the genus Synapturanus is well ossified, with very little cartilaginous areas, mostly restricted to the nasal capsule and tympanic ring. Osteological description of Synapturanus latebrosus sp. nov. is based on male specimen SINCHI-A 2679, variation with male SINCHI-A 842 is noted and compared with an adult female of S. sacratus sp. nov. (ICN 56893). The skull of S. latebrosus sp. nov. is overall triangular, slightly longer than wide (Fig. 9A, B, and C) and widest at the level of the jaw articulation. The jaw articulation lies at the most anterior edge to the otic capsule. The planum anterorbitalis is ossified and oriented anterolaterally forming the posterolateral walls of the nasal capsules and the anterior wall of the orbits. The auditory capsules, except its most anteroventral edge that is mostly cartilaginous, and the crista parotica are fully ossified. Between the anteroventral cartilaginous edge of the otic capsule and the crista parotica, lies a large and cartilaginous operculum; by transparency a large fenestra ovalis is clearly visible. From the most anterior edge of the operculum and running horizontally, between the crista parotica and the cartilaginous anterior edge of the otic capsule, lies the ossified columella. The columella then bends slightly ventrally towards the squamosal, before reaching the posterior edge of the squamosal, it articulates with a cartilaginous externa plectri that connects with the cartilaginous tympanic ring. The tympanic ring is not complete, but lack its dorsoposterior third. Endocranium. Sphenethmoid. The paired sphenethmoid are well developed, fused into a single bone, ossified, and form the anterolateral wall of the neurocranium and the anterior margin of the optic fenestra. Dorsally, the sphenethmoid is mostly covered by the nasals and frontoparietals and only visible between the nasals and the frontoparietals. Ventrally, it is visible anteriorly and posteriorly on both sides of the cultriform process of the parasphenoid and forming the ventral border of a very large optic fenestra. Anteriorly it does not reach the posterior border of the choanae. Posterolaterally, the sphenethmoid indistinguishable fuses with prootic and surrounds the optic fenestra. Prootics and exoccipitals. The prootics are fused with the exoccipitals contributing to the posterior part of the braincase, both are well ossified. The prootic ossifies on the posterolateral wall of the neurocranium, forming the dorsal and posterior margin of the optic foramen and entirely enclose the prootic foramen. Dorsally, their anteromedial margins are overlapped by the frontoparietals. Ventrally, the medial and posterior margins of the prootic are overlapped by the parasphenoid. The prootics also form the anterior and ventrolateral walls of the otic capsules; dorsally they form the epiotic eminences. The epiotic eminences are ossified, large, and visible; medially they fuse gradually to the skull. Most of the ossified crista parotica does not extend beyond the level of the otic capsule; however, a small distinct extension is found on the anterolateral corner of the crista parotica. The otic capsule is mostly ossified except in its most anteroventral area. A relatively large prootic foramen lies on the anteroventral surface of the otic capsule. In anurans, usually smaller oculomotor and trochlear foramina are found between the optic fenestra and prootic fenestra; these two foramina are not visible in S. latebrosus, and likely were integrated to the large optic fenestra. The exoccipitals form the posterior part of the otic capsules, the margins of the foramen magnum, and the occipital condyles. Dorsally, the exoccipitals are largely overlapped by the frontoparietals and ventrally by the alae and posteromedial process of the parasphenoid. The exoccipitals are only visible forming the dorsal and ventral edge of the foramen magnum and the occipital condyles. The occipital condyles bear oval-shaped articular surfaces. Plectral apparatus. The plectral apparatus is found ventral to the crista parotica. The columella (pars media plectri) is a long, cylindrical bone, that proximal to the operculum has an expanded base, and runs almost horizontally and then it bends slightly and gradually ventrally towards the squamosal to about half the height of the squamosal. Distally, it connects with the cartilaginous pars externa plectri which is surrounded by a dorsally incomplete and wide ring, the cartilaginous tympanic annuli. The proximal end of the columella contacts with the anterodorsal edge of the cartilaginous operculum. The operculum is well developed, cartilaginous, and occludes the large fenestra ovalis. Exocranium. Frontoparietals. The broad, large, and paired frontoparietal bones are narrowly separated medially along their length and completely roofing the frontoparietal fenestra. The frontoparietals do not contact with the nasal bones and overlap the sphenethmoid. The anterior tip of the frontoparietals is close to the midline and from there they slant outwardly and posteriorly to the anterodorsal edge of the orbit. Posteriorly the frontoparietals extend over the prootic, partially overlap the epiotic eminences, and the exoccipitals. In specimen SINCHI 842, the separation of the frontoparietals is much narrower on its posterior 1/3. Nasal. The paired nasals are extensive and well-ossified bones, they cover the nasal capsule and the sphenethmoid, they are medially separated, and do not contact with the frontoparietals. From the midline, they extend posteriorly slanted in a 45-degree angle to reaching the dorso-anterior edge of the orbit. The nasals cover the olfactory capsules and curve ventrolateral to about half the diameter of the external nostril (they do not reach the maxillae) and then turn upward over and dorsally surrounding the nasal capsule. Dorsally, between the anterior tip of the nasals and between the anterior tip of the cartilaginous nasal capsule, a thin ossification of the septum nasi is visible between the nasals with its apex directed posteriorly. Parasphenoid. The large parasphenoid lacks ornamentation. The cultriform process is, Published as part of Osorno-Muñoz, Mariela, Gutiérrez-Lamus, Doris L., Lynch, John, Keeffe, Rachel, Caicedo-Portilla, José Rancés, Chan, Kin Nok, Tonini, João F. R. & De Sá, Rafael O., 2023, Three new species of the Synapturanus rabus complex (Microhylidae: Otophryninae) in Colombia with a review of the genus Synapturanus, pp. 151-196 in Zootaxa 5258 (2) on pages 157-175, DOI: 10.11646/zootaxa.5258.2.1, http://zenodo.org/record/7777048, {"references":["Pyburn, W. F. (1975) A new species of microhylid frog of the genus Synapturanus from southeastern Colombia. Herpetologica, 31, 439 - 443."]}